The Transgenic Animal Facility provides UW Cancer Center staff with the capacity to manipulate the genome of experimental animals used in cancer research. The efficient generation of knockout or transgenic animals requires specialized technical skills in the areas of animal husbandry and surgery, embryology, embryonic stem culture and gene targeting vectorology, embryo micro-manipulation, and cryopreservation. In addition, the procedures require sensitive and expensive microscopic equipment as well as SPF-animal facilities. Because these requirement cannot be met by most individual investigators in their own laboratories, the gene targeting and transgenic animal technologies must be provided by common resource facilities. At the University of Wisconsin, that resource is the Transgenic Animal Facility (TAF). The cancer research performed at UWCCC relies heavily upon this resource. For that reason, funds are requested to support this critical activity.